To save credits you must do the following. 1. After you have earned some
money from either a mission or an arena battle save the game. 2. Load
your game and do any mission you like. 3. If you fail your mission and
get less credits, go to the system and exit the game WITHOUT saving it!
4. When you go back to your game, you will have the amount of credits
you had before you failed the mission and also you would still have your
debt on the mission because the fail you did earlier wouldn't count. You
could save tons of credits this way. HAPPY SAVINGS !

NOTE: If your going to use this cheat only go straight to mission or
else you could lose what else you did before the mission. e.g. If you
buy a new part and then go to mission and fail then not save the game,
you'll lose the A.C part you bought.